901 resultados para Classification of water bodies
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Abstract Rain gardens are an important tool in reducing the amount of stormwater runoff and accompanying pollutants from entering the city’s streams and lakes, and reducing their water quality. This thesis project analyzed the number of rain gardens installed through the City of Lincoln Nebraska Watershed Management’s Rain Garden Water Quality Project in distance intervals of one-eighth mile from streams and lakes. This data shows the distribution of these rain gardens in relation to streams and lakes and attempts to determine if proximity to streams and lakes is a factor in homeowners installing rain gardens. ArcGIS was used to create a map with layers to determine the number of houses with rain gardens in 1/8 mile distance increments from the city’s streams and lakes and their distances from a stream or lake. The total area, number of house parcels, and the type and location of each parcel type were also determined for comparison between the distance interval increments. The study revealed that fifty-eight percent of rain gardens were installed within a quarter mile of a stream or lake (an area covering 60% of the city and including 58.5% of the city’s house parcels), and that eighty percent of rain gardens were installed within three-eighth mile of streams or lakes (an area covering 75% of the city and 78.5% of the city’s house parcels). All parcels in the city are within 1 mile of a stream or lake. Alone the number of project houses per distance intervals suggested that proximity to a stream or lake was a factor in people’s decisions to install rain gardens. However, when compared to the number of house parcels available, proximity disappears as a factor in project participation.
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Histological and ultrastructural analyses of gills were observed in Nile tilapia collected from three different waterbodies in southeast Brazil: an urban lake in a park in the city of São Paulo, a reservoir in a rural city, and a commercial aquaculture facility. These aterbodies were analyzed and classified as hypereutrophic, eutrophic, and supereutrophic, respectively, with 310.00, 94.00, 28.00 of phosphate (PO2_ 4 lg L _1) and 65.49, 24.95, 12.83 of chlorophyll (lg L _1). A significant difference in the histological alterations index (HAI) was observed only in fish from the urban lake, with the presence of cell hypertrophy, hyperplasia, aneurism, and other alterations. When compared to the other groups, a large quantity of rodlet cells was also observed in the urban group. These results demonstrate the correlation of eutrophic states of water with gill morphology. Also discussed is the premise that large amounts of organic material dissolved in water can alter the morphology of the fish gills
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Mode of access: Internet.
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Mode of access: Internet.
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We describe the diversity of aquatic invertebrates colonising water-filled final voids produced by an open-cut coal mine near Moura, central Queensland. Ten disused pits that had been filled with water from < 1 year to 22 years prior to the survey and three nearby 'natural' water bodies were sampled in December 1998 and again in March 1999. All invertebrates collected were identified to family with the exception of oligochaetes, cladocerans, ostracods and copepods, which were identified to these coarser taxonomic levels. Sixty-two taxa were recorded from > 20 000 individuals. The greatest familial richness was displayed by the Insecta (33 families) followed by the mites (Acari) with 12 families. While natural water bodies held the greatest diversity, several mine pits were almost as rich in families. Classification analyses showed that natural sites tended to cluster together, but the groupings did not clearly exclude pit sites. Mining pits that supported higher diversity tended to be older and had lower salinity (< 2000 mu S/cm); however, salinity in all water bodies varied with rainfall conditions. We conclude that ponds formed in final voids at this mine have the potential to provide habitat for many invertebrate taxa typical of lentic inland water bodies in central Queensland.
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This thesis presents an investigation into the application of methods of uncertain reasoning to the biological classification of river water quality. Existing biological methods for reporting river water quality are critically evaluated, and the adoption of a discrete biological classification scheme advocated. Reasoning methods for managing uncertainty are explained, in which the Bayesian and Dempster-Shafer calculi are cited as primary numerical schemes. Elicitation of qualitative knowledge on benthic invertebrates is described. The specificity of benthic response to changes in water quality leads to the adoption of a sensor model of data interpretation, in which a reference set of taxa provide probabilistic support for the biological classes. The significance of sensor states, including that of absence, is shown. Novel techniques of directly eliciting the required uncertainty measures are presented. Bayesian and Dempster-Shafer calculi were used to combine the evidence provided by the sensors. The performance of these automatic classifiers was compared with the expert's own discrete classification of sampled sites. Variations of sensor data weighting, combination order and belief representation were examined for their effect on classification performance. The behaviour of the calculi under evidential conflict and alternative combination rules was investigated. Small variations in evidential weight and the inclusion of evidence from sensors absent from a sample improved classification performance of Bayesian belief and support for singleton hypotheses. For simple support, inclusion of absent evidence decreased classification rate. The performance of Dempster-Shafer classification using consonant belief functions was comparable to Bayesian and singleton belief. Recommendations are made for further work in biological classification using uncertain reasoning methods, including the combination of multiple-expert opinion, the use of Bayesian networks, and the integration of classification software within a decision support system for water quality assessment.
Biogeochemical Classification of South Florida’s Estuarine and Coastal Waters of Tropical Seagrasses
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South Florida’s watersheds have endured a century of urban and agricultural development and disruption of their hydrology. Spatial characterization of South Florida’s estuarine and coastal waters is important to Everglades’ restoration programs. We applied Factor Analysis and Hierarchical Clustering of water quality data in tandem to characterize and spatially subdivide South Florida’s coastal and estuarine waters. Segmentation rendered forty-four biogeochemically distinct water bodies whose spatial distribution is closely linked to geomorphology, circulation, benthic community pattern, and to water management. This segmentation has been adopted with minor changes by federal and state environmental agencies to derive numeric nutrient criteria.
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Control and management of Uganda fishery resources has been hindered by among other factors the multispecies nature of the resource and the characteristic behaviour of the fishing communities. Fishermen have both genuine and uncompromising attitudes as to why they carry out certain fishing technologies. All fishing activities aim at maximizing the catches or profits while others may fish on a small scale for subsistence. Sensitizing the" fisherfolk on the appropriate fishing technologies, importance of awell regulated fishery exploitation and their participation in control and management of the resource would enhance or lead to increased and sustainable fish production. Socio-economics of fishing technologies were therefore examined using prepared questionnaires and reasons why the fishing communities behave the way they do established.
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Control and management of Uganda fishery resources has been hindered by among other factors the multispecies nature of the resource and the characteristic behaviour of the fishing communities. Fishermen have both genuine and uncompromising attitudes as to why they carry out certain fishing technologies. All fishing activities aim at maximizing the catches or profits while others may fish on a small scale for subsistence. Sensitizing the" fisherfolk on the appropriate fishing technologies. importance of awell regulated fishery exploitation and their participation in control and management of the resource would enhance or lead to increased and sustainable fish production. Socio-economics of fishing technologies were therefore examined using prepared questionnaires and reasons why the fishing communities behave the way they do established.
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Current Brazilian law regarding water fluoridation classification is dichotomous with respect to the risks of and benefits for oral diseases, and fluoride (F) concentrations less than 0.6 or above 0.8 mg F/L are considered outside the normal limits. Thus, the law does not consider that both caries and fluorosis are dependent on the dosage and duration of fluoride exposure because they are both chronic diseases. Therefore, this study evaluated the quality of water fluoridation in Maringá, PR, Brazil, considering a new classification for the concentration of F in water the supply, based on the anticaries benefit and risk of fluorosis (CECOL/USP, 2011). Water samples (n = 325) were collected monthly over one year from 28 distribution water networks: 20 from treatment plants and 8 from artesian wells. F concentrations were determined using a specific ion electrode. The average F concentration was 0.77 mg F/L (ppm F), ranging from 0.44 to 1.22 mg F/L. Considering all of the water samples analyzed, 83.7% of them presented from 0.55 to 0.84 mg F/L, and according to the new classification used, they would provide maximum anticaries benefit with a low risk of fluorosis. This percentage was lower (75.4%) in the water samples supplied from artesian wells than from those distributed by the treatment plant (86%). In conclusion, based on the new classification of water F concentrations, the quality of water fluoridation in Maringá is adequate and is within the range of the best balance between risk and benefit.
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The properties of recycled aggregate produced from mixed (masonry and concrete) construction and demolition (C&D) waste are highly variable, and this restricts the use of such aggregate in structural concrete production. The development of classification techniques capable of reducing this variability is instrumental for quality control purposes and the production of high quality C&D aggregate. This paper investigates how the classification of C&D mixed coarse aggregate according to porosity influences the mechanical performance of concrete. Concretes using a variety of C&D aggregate porosity classes and different water/cement ratios were produced and the mechanical properties measured. For concretes produced with constant volume fractions of water, cement, natural sand and coarse aggregate from recycled mixed C&D waste, the compressive strength and Young modulus are direct exponential functions of the aggregate porosity. Sink and float technique is a simple laboratory density separation tool that facilitates the separation of cement particles with lower porosity, a difficult task when done only by visual sorting. For this experiment, separation using a 2.2 kg/dmA(3) suspension produced recycled aggregate (porosity less than 17%) which yielded good performance in concrete production. Industrial gravity separators may lead to the production of high quality recycled aggregate from mixed C&D waste for structural concrete applications.
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Due to its wide industrial use, chromium (Cr) is considered a serious environmental pollutant of aquatic bodies. in order to investigate the ecophysiological responses of water hyacinth [Eichhornia crassipes (Mart.) Solms] to Cr treatment, plants were exposed to 1 and 10 mM Cr(2)O(3) (Cr(3+)) and K(2)Cr(2)O(7) (Cr(6+)) concentrations for two or 4 days in a hydroponic system. Plants exposed to the higher concentration of Cr(6+) for 4 days did not survive, whereas a 2 days treatment with 1 mM Cr(3+) apparently stimulated growth. Analysis of Cr uptake indicated that most of the Cr accumulated in the roots, but some was also translocated and accumulated in the leaves. However, in plants exposed to Cr(6+) (1 mM), a higher translocation of Cr from roots to shoots was observed. it is possible that the conversion from Cr(6+) to Cr(3+), which immobilizes Cr in roots, was not total due to the presence of Cr(6+), causing deleterious effects on gas exchange, chlorophyll a fluorescence and photosynthetic pigment contents. Chlorophyll a was more sensitive to Cr than chlorophyll b. Cr(3+) was shown to be less toxic than Cr(6+) and, in some cases even increased photosynthesis and chlorophyll content. This result indicated that the F(v)/F(0) ratio was more effective than the F(v)/F(m) ratio in monitoring the development of stress by Cr(6+). There was a linear relationship between qP and F(v)/F(m). No statistical differences were observed in NPQ and chlorophyll a/b ratio, but there was a tendency to decrease these values with Cr exposure. This suggests that there were alterations in thylakoid stacking, which might explain the data obtained for gas exchanges and other chlorophyll a fluorescence parameters. (C) 2008 Elsevier B.V. All rights reserved.
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In order to classify mosquito immature stage habitats, samples were taken in 42 localities of Córdoba Province, Argentina, representing the phytogeographic regions of Chaco, Espinal and Pampa. Immature stage habitats were described and classified according to the following criteria: natural or artificial; size; location related to light and neighboring houses; vegetation; water: permanence, movement, turbidity and pH. Four groups of species were associated based on the habitat similarity by means of cluster analysis: Aedes albifasciatus, Culex saltanensis, Cx. mollis, Cx. brethesi, Psorophora ciliata, Anopheles albitarsis, and Uranotaenia lowii (Group A); Cx. acharistus, Cx. quinquefasciatus, Cx. bidens, Cx. dolosus, Cx. maxi and Cx. apicinus (Group B); Cx. coronator, Cx. chidesteri, Mansonia titillans and Ps. ferox (Group C); Ae. fluviatilis and Ae. milleri (Group D). The principal component analysis (ordination method) pointed out that the different types of habitats, their nature (natural or artificial), plant species, water movement and depth are the main characters explaining the observed variation among the mosquito species. The distribution of mosquito species by phytogeographic region did not affect the species groups, since species belonging to different groups were collected in the same region.